This is the most recent announcement coming this part of Africa. These are likely associated with the spread of polio from endemic Nigeria to its neighboring countries. According to the Global Polio Eradication Initiative, the epidemic first spread from polio-endemic Nigeria to its polio-free neighbors in 2008 and is still paralyzing children in West and Central Africa.

Nine countries – Burkina Faso, Cameroon, Chad, Guinea, Liberia, Mali, Mauritania, Senegal and Sierra Leone – are considered to have active outbreaks of polio (i.e. cases within the last six months).

Polio is caused by the poliovirus types 1, 2 and 3. All three types cause paralysis, with wild poliovirus type 1 being isolated from paralysis cases most often.

This viral infection is primarily spread from person to person through the fecal-oral route. However, in places where sanitation is very good, transmission though throat secretions may be considered more important.

Polio is recognized in about 1 percent of infections by flaccid paralysis, while over 90 percent of infections are unapparent.

Paralysis of poliomyelitis is usually asymmetric and the site of paralysis depends on the location of nerve cell destruction on the spinal cord or brain stem. Legs are affected more often than the arms.

Paralysis of the respiration can be life threatening.

Polio must be differentiated from other paralytic diseases like botulism and Guillain-Barre Syndrome.

With immunization, by the end of 2007, polioviruses were limited to only four countries who had not succeeded in interrupting transmission; Afghanistan, India, Nigeria and Pakistan. But as mentioned above, the risk of importation of polio remains a problem.